Automatic electric-circuit breaker



H. E WADSWORTH AND W. B. ENSIGN.

AUTOMATIC ELECTRIC CIRCUIT BREAKER.

I APPLICATION FILED JAN- IZ; IQZO- 1 ,359,298. Patented Nov. 16, 1920.

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flttoameg UNITED STATES PATENT OFFICE.

HARRY E. WADSWORTH, OF NEW YORK, AND WILLIAM B. ENSIGN, 0F WHITE PLAINS,

NEW YORK.

AUTOMATIC ELECTRIC-CIRCUIT BREAKER.

Specification of Letters Patent.

Patented Nov. 16, 1920.

Application filed January 12, 1920, Serial No. 350,966.

To all whom it may concern:

Be it known that we, HARRY E WADS- WORTH, a citizen of the United States, and a resident of the borough and county of Bronx, city and State of New York, and WILLIAM ENSIGN, a citizen of the United States, and a resident of White Plains, county of VVestchester, and State of New York, have invented certain new and useful Improvements in Automatic Electric-Circuit Breakers, of which the following is a specification. I 7

Our improvements relate to means for automatically breaking or opening an elec tric circuit when a predetermined excess of current occurs, substantially as set forth in our concurrent application Serial No. 314,552, filed July 31, 1919, the object, as in that case. being primarily to dispense with cut-out fuses by providing an equivalent therefor to be positioned in like manner hetween the usual spring clip terminals; to

effectually protect the operative parts and prevent tampering therewith, etc.,-our invention in the present case consisting in the construction, combination and arrangement of parts herein described and claimed specifically, whereby these desired results are attained; and a distinctive feature in the present case being the trip lever mechanism employed to effect a forceful and instantaneous break of circuit whenever the latter employment of knife blade contacts, in con-' junction with a contactual rock lever, wherer by the contact breaks are multiplied and spark danger thereby lessened, all as hereinafter fully set forth.

. In the accompanying drawings,

Figure 1, is a front elevation of our improved circuit breaker; i

Fig. 2. is an end elevation thereof;

Fig. 3, is a front view of our circuit breaker as mounted between knife blade circuit terminals;

Fig. 4, is a central longitudinal sectional elevation taken substantially.uponplane of line 44, Fig. 1, showing the operative parts as set when the electric circuit is closed;

Fig. 5, is a like view showing the contactual rock lever tripped as when the air cuit is broken;

Fig. 6. is a view like unto Fig. 4, illustrating the resetting operation;

Fig. 7 is a sectional elevation taken upon plane of line 7-7, Fig. 4,.

The casing of insulating material is made in two parts G, 0, each forming one half of the basic structure, and each being substantially a reversed. duplication of the other. The extremities of each half are semi-circular, so that when the halves'are fitted together cylindrical ends are formed over which the cylindrical metallic ferrule caps F, F, fit, binding the two said nonconductive parts C, C, of the housing to gether. These parts 0, C, are further secured together by the rigidly mounted cross I bar B, and further, if desired, by screws or bolts for which holes 0, 0, may be provided as indicated in Figs. 4, 5 and 6. a

One of the ferrule caps, F, is a fixture upon its end of the casing C, C, being The medial portions of the halves C, C.

of the non-conductive casing are formed with coincidental lateral extensions C", and are recessed to afford operative space for the contactual rock lever B. which is fulcrumed centrally on the cross bar B, aforesaid. That is to say, the metallic contacts m, m, mounted on the arms 7*, r. of the rock lever are equidistant from the fulcrum thereof,the-body of the lever itself being made of hard fibrous or other suitable nonconductive material. A spring tends'constantly to draw the rock lever R, into thevertical position shown in Fig. 5, with its upper arm 1', resting against a stop a, pro vided for the purpose. The lower arm r,

of the rock lever R, is of segmental shape,

and is formed with. a bearing shoulder 1*, for engagement with the free end of a latch arm e, as shown inFig-s. 4 and 6, said latch arm 6. being pivotally supported at e, and being held normally against a stop 6, by a spring e. The lower arm 1", of the rock 7 stop a.

lever B, is also formed with a transverse slot 7 for the accommodation of a lateral projection (Z, on the free end of a retractor link (Z, the other end of which is pivotally connected to a slide 7, rigidly secured to the movable ferrule cap F, the parts C, C, being recessed to accommodate and support said slide f.

Also rigidly attached to the movable terrule cap F is the bifurcated terminal f likewise supported slidably in coincident recesses in the opposed faces of the two parts C, C, of the casing.

Pivotally supported at b, on the same fulcrum as that of the latch arm 6, is the trip lever i formed with a kick off toe 25, for contacting with the said latch arm a, when the trip lever t, is actuated by the electroanagnet M.

The winding of the electro-magnet M, is included in the electric circuit, so that any intensity of current over a prescribed degree will cause its core to attract and pull over the trip lever 2 against the resistance of the retractile spring 25 which tends constantly to hold said trip lever 6, against a stationary part, as "for instance, the protuberant stop a, on the casing.

It, is, are terminal clips, one of which is in electrical connection with the stationary ferru e cap F, the other with the circuit wire from the electro-magnet M, so that in the absence of the metallic knife blade contact 771, between said terminal clips 7a, the circuit is broken.

The operation is as follows:-The parts beine: in the relative positions shown in Fig. 4. with the circuit passing between ferrule caps F, from one to the other through he bifurcated terminal f contact an, electro-magnet M, terminal clips lab, and contact m, as under prescribed normal conditions, any abnormal increase of current will energize the ele'ctro-magnet M, sufficiently to suddenly pull the trip lever 1%, over toward it against the resistance of the spring t. As a result the kick off toe t, impinges with force against'the latch arm a, knocking it out of engagement with the bearing shoulder r against the resistance of the spring 6 thereby allowing the "spring a, torock the lever R, into the position shown in Fig. '5, with its upper arm 1*, resting against the This of course withdraws the metallic contact m,'irom engagement with the terminal clips '70, 7c, and the metallic contact m, from engagement with the'bifurcated terminal f simultaneously, thus openingthe circuit.

To re-settheparts the device is removed bodily from the maincircuit terminal connections, and "the'movabl e ferrule cap F, is

partly withdrawn from its normal position, on-1ts end o't'the casing, the motion bemg llmited by a stop s,or-otherw1se. The opening of the circuit has of course de-magnetized the electro-magnet M, so that the spring t", has returned the trip lever t, to normal position against the stop 0, thereby allowing the spring 6 to return the latch arm (2, to its normal position, resting against the stop 6 Hence, when the aforesaid partial withdrawal of the movable ferrule cap F, takes place, causing the retractor link 1], to draw the contactual rock lever R, back into normal position against .the resistance of the spring a, the bearing shoulder 1- in passing will depress the free end of the latch arm 6, slightly against the resistance of the spring a which latter will then return the latch lever to normal position against its stop 0 with the free end of said latch arm (3, again in engagement with the said hearing shoulder r on the rock lever B, as shown in Fig. 6, thus locking said rock lever in contactual position, with its upper metallic contact at, between the terminal clips it, it, and its lower metallic contact m, in position for engagement with and between the arms of the bifurcated terminal 7"; when the ferrule cap F, is again returned to its normal position on its end of the casing, thus restoring all the parts to reset closedcircuit relationship, so that when the device is re-inserted between the main circuit terminals the electric current will be tree to pass as long as it does not again exceed a degree of intensity prescribed by thewindinn ot the coil on the electro-magnet M.

By thus providing for the use of knife blade make and break connections we ruini- IlliZO the intensity of arc flash by subdividing: and distributing it, so that the sparking isrendercd comparatively harmless.

As in the case of our cut-out slide circuit breaker described in said concurrent application Serial No. 31 1,5352, it will be seen that in our present device the switch latch may be reset, when the device is removed from between the terminal clips, without opening the casing, and by the simple expedient of reciprocating a portion thereof,

Furthermore all the operative parts of the circuit breaker are inclosed, isolated and protected from contact with extraneous objects, and they cannot be tampered with or improperly manipulated while the incasement is intact. The device is an effectual substitute for-the blow-out fuse, with the great advantage that it can be re set and used indefinitely; and the act of resetting simply involves its removal from between the circuit terminal clips and the manipulation ofthejerrule cap F, after which it is ready for replacement in operative position.

\Vhatwe claim as our invention and desire to secure'by Letters Patent is,

An automatic electric circuit breaker of the character designated, comprising :1 casing of insulating material, metallic ferrule caps formed externally for contactual engagement with main electric circuit terminal spring clip, internal electric clip terminals connected with each of said ferrule ca s, a rock levr of non-conductive materia on which are mounted metallic closure contacts for engagement with said internal sprin clips, means which tend constantly to me said contactual lever out of engagement with said internal electric terminal clips, a spring latch arm adapted to lock said rock lever in normal position, a trip lever adapted to un lock said spring latch arm, an electro-magnet interposed in the circuit and adapted to actu- 15 ate said trip lever, and ferrule-connected means for re-settin the parts after a break of the circuit, for t 1e purpose described.

HARRY E. WADSWORTH. WILLIAM B. ENSIGN. Witnesses:

GEO. WM. MIATI, DOROTHY Mm'rr, L. H. BRADLEY. 

